Cutting performance and indentation behaviour of diamond films on co-cemented tungsten carbide

Diamond films were grown by Hot Filament Chemical Vapour Deposition (HFCVD) on differently pretreated ISO-grade K10 cemented carbide (WC-5.8 wt.%Co) c utting inserts. Etching with diluted HNO3 and surface roughening by Murakam i's reagent were used as substrate pretreatments. The adhesion of the films was evaluated by indentation tests. In order to obtain a reliable estimati on of the adhesion by the slope of the crack radius-indentation load curves , a careful SEM measurement of the crack lengths was performed. Bare and di amond-coated cutting inserts were used for turning tests of Al2O3-reinforce d aluminum alloy. The adhesion levels obtained from the indentation curves correlated well the lifetime of diamond-coated cutting inserts used in turn ing tests performed on metal matrix composite material under severe cutting conditions, (C) 2000 Elsevier Science S.A. All rights reserved.